Alignment method and mounting method using the alignment method

ABSTRACT

Positioning recognition marks are read by movable recognition device for positioning objects to be bonded to each other. An alignment method includes a step of reading the recognition marks during movement of the recognition device before its complete stop, and a step of identifying absolute positions of the recognition marks by correcting the mark recognition positions having been read based on a position feedback signal of the moving recognition device. A mounting method using the alignment method is also disclosed. It is possible to maintain a high alignment accuracy, eliminate necessity of assuring a settling time for complete stop of the movable recognition device, and significantly reduce the alignment time and mounting tact.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. Patent ApplicationNo. 10/509,882 filed on Oct. 4, 2004, currently pending, which was theNational Stage of International Application No. PCT/JP03/03880, filed onMar. 27, 2003. The disclosures of U.S. patent application Ser. No.10/509,882 and International Application No. PCT/JP03/03880 are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an alignment method for positioningobjects to be bonded to each other and a mounting method using thealignment method.

2. Discussion of the Related Art

For bonding objects to each other, for example, for bonding a chip to asubstrate, relative positions between both objects have to be aligned ata high accuracy. For this alignment, recognition marks for positioningare provided on at least one object, usually, on both objects, thepositions of the recognition marks are read by recognition means such asa camera and the recognition marks are positioned to each other, andwhereby, the relative relationship in position between both objects isset within a predetermined accuracy.

In such an alignment, for example, in a case where an object isrelatively large, recognition marks provided on both end portionsthereof and the like are read by moving the recognition means, and basedon the reading information, both objects are positioned to each other.

As shown in FIG. 1 for example, a two-sight recognition means 5 havingsights in upward and downward directions is inserted between a firstobject 2 (for example, a chip) held on a head 1 and a second object 4(for example, a substrate) held on a stage 3. The two-sight recognitionmeans 5 has a two-sight optical system, for example, on an almostidentical vertical axis. After a recognition mark A on first object 2and a recognition mark C on second object 4 are read by moving two-sightrecognition means 5, a recognition mark B on first object 2 and arecognition mark D on second object 4 are read by moving two-sightrecognition means 5. Based on the reading information, for example, theposition and posture of stage 3 are adjusted, thereby setting therelative positional accuracy between both objects within a predeterminedaccuracy.

In a conventional technology in such an alignment, when upper and lowerrecognition marks A, C (or B, D) are read, for example, as shown in FIG.2, after two-sight recognition means 5 is moved to a predeterminedreading position P1, a settling time T for complete stop of therecognition means 5 is assured, and the reading accuracy is assured byreading the marks after the complete stop after the settling time T.

However, if the settling time T is assured as described above, becauseat least about 0.1 to 1 second is taken for the settling time T, thereis a limit for shortening the time up to the completion of thealignment, ultimately, a mounting tact for mounting the objects.

Further, if the recognition mark is read at an incomplete stop conditionof the object, as shown in FIG. 3 for example, the recognition mark readduring the movement may be recognized as a mark F enlarged by beingextended in the movement direction X ascribed to the influence of themovement speed, as compared with a positioning recognition mark Erecorded at a complete stop condition. In reading of the positioningrecognition mark E, this phenomenon occurs, for example, when a shutterspeed is set at about 1/100 second or more. If recognized under thecondition of mark F thus enlarged based on the recorded recognition markE, the accuracy for the position recognition reduces.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide analignment method which can maintain a high alignment accuracy and whichcan greatly shorten alignment time and mounting tact by eliminating thenecessity for assuring a settling time as described above, and amounting method using the alignment method.

Another object of the present invention is to prevent reduction ofaccuracy for recognizing positions of recognition marks, while achievingshortening of alignment time and mounting tact.

To accomplish the above objects, an alignment method according to thepresent invention for positioning objects to be bonded to each other byreading a positioning recognition mark provided on at least one objectby movable recognition means, comprises the steps of reading therecognition mark during movement of the recognition means before itscomplete stop; and identifying an absolute position of the recognitionmark by correcting a mark recognition position having been read by therecognition means, based on a position feedback signal of therecognition means sent during movement of the recognition means (a firstalignment method). Namely, even if the recognition mark is read duringmovement of the recognition means before its complete stop, as long asthe position feedback signal of the recognition means during itsmovement, that is, a coordinate of a moving axis at the time of markreading, is precisely fed back, by correcting the mark position at thetime of mark reading based on the feedback signal, an absolute positionof the recognition mark at that time can be identified accurately.Because reading during movement becomes possible, it becomes unnecessaryto assure a settling time before complete stop as required in aconventional technology, the alignment time, ultimately, the time formounting, can be shortened greatly.

Further, the present invention also provides a basic technical conceptto read both recognition marks simultaneously and synchronously, fromthe viewpoint of increasing an alignment accuracy as well as greatlyshortening the alignment time, ultimately, the mounting time. Namely, analignment method according to the present invention for positioningobjects to be bonded to each other by reading positioning recognitionmarks provided on both objects by a two-sight recognition means havingsights in directions toward both objects, comprises a step of readingboth of the recognition marks simultaneously and synchronously with eachother (a second alignment method). By thus reading both of therecognition marks provided on both objects simultaneously andsynchronously using a two-sight recognition means, even if the two-sightoptical system vibrates by the movement and there is an error betweenthe read information and the coordinate of the moving axis to be taken,the relative positional relationship between the upper and lowerrecognition marks can be maintained because they are read synchronously,the alignment accuracy increases as compared with a conventional methodwherein an accuracy of axis stopping is added to an alignment accuracy.

Therefore, even in the above-described first alignment method accordingto the present invention, it is preferred that a recognition meanshaving sights in directions toward both objects, for example, atwo-sight recognition means, is used as the movable recognition means,respective positioning recognition marks provided on both objects aresimultaneously read synchronously as to respective sights duringmovement of the recognition means before its complete stop, and absolutepositions of respective recognition marks are identified by correctingrespective mark recognition positions having been read by therecognition means, based on position feedback signals of the recognitionmeans sent during movement of the recognition means. Because theabsolute positions can be identified, it becomes also possible to carryout a correction in a rotational direction (θ direction). By this,because the reading accuracy is high and the absolute positions of themarks can be recognized, a further high accuracy alignment becomespossible, and shortening of mounting time becomes possible.

Further, in the above-described first alignment method according to thepresent invention, a method may be also employed wherein recognitionmeans for reading all of the respective positioning recognition marksprovided on both objects from lower side is used as the above-describedmovable recognition means, respective recognition marks are read duringmovement of the recognition means before its complete stop, and absolutepositions of respective recognition marks are identified by correctingrespective mark recognition positions having been read by therecognition means, based on position feedback signals of the recognitionmeans sent during movement of the recognition means. A double lenscamera can also be used as this movable recognition means disposed at alower-side position. As such a double lens camera, a camera incorporatedintegrally into a movement mechanism of the camera, namely, incorporatedintegrally at a constant positional relationship can be used.Alternatively, the double lens camera may be constructed byincorporating two cameras being separable into a movement mechanism.Further, a method can also be employed wherein a positioning recognitionmark provided on at least one object is read by transmitting ameasurement wave (for example, a visual ray or an infrared ray) throughan object or/and a member for receiving the object. The object or themember for receiving the object capable of transmitting a measurementwave is formed, for example, from a glass.

In the above-described first alignment method, it is preferred that thereading is carried out by software revision of an aberration of a lensof the movable recognition means. In a case where a camera mechanismhaving a lens is used as the movable recognition means, if merely readbefore a complete stop during movement, because there occurs a casewhere the mark is read at a time when the mark has not yet reached thecenter of the camera, when there is an aberration or distortion of alens, it causes an error in recognition of a position. Therefore, if thedistortion of the lens is corrected, for example, by storing a referencematrix mark in a software matrix, even in reading at a position otherthan the lens center, it becomes possible to recognize an accurateposition and to prevent an obstacle to improve the accuracy.

In the above-described first and second alignment methods, a method canbe employed wherein, when recognition marks of both objects are providedat positions impossible to read simultaneously, a recognition markprovided on one object is moved together with the object to a positionat which the recognition mark can be read simultaneously with arecognition mark provided on the other object, and after bothrecognition marks are simultaneously read synchronously, an absoluteposition of the moved recognition mark is identified by correction inconsideration of an amount of the movement.

In this method, it is preferred that, when the object is moved to theposition possible to be read simultaneously, the object reaches arecognition position prior to the movable recognition means, or theobject reaches a recognition position simultaneously with the movablerecognition means. Further, it is preferred that, when the object ismoved to the position possible to be read simultaneously, an absoluteposition of the recognition mark of the object is identified before acomplete stop of a table for moving the object, based on a positionfeedback signal of the table.

Namely, when the recognition means is stopped, the means is huntingduring a settling time. Further, even if the table is stopped, because astructural material may bend and vibrate, the recognition accuracy ofthe absolute position may be influenced. Therefore, if it is duringmovement at a constant speed rather than being stopped, no vibrationoccurs, and as long as only the position feedback signal can beprecisely recognized, the recognition accuracy of the absolute positionincreases. Further, in a case where the object is moved to the positionpossible to be read simultaneously, the movement of the object must becompleted before the recognition means reaches the position, where it ispossible to be read simultaneously. If the movement of the object islate, it is necessary that the recognition means stops and waits. If so,a vibration may occur as described above and the recognition accuracy ofthe absolute position may be influenced. Therefore, the movement timingand the movement speed of the recognition means are adjusted beforehand,so that the object is reached prior to the recognition means. Further, acondition, where during the movement of the object, the recognitionmeans is also during movement, and they cross just at a readingposition, can realize a timing capable of measuring at a best conditionin vibration. If such a condition is calculated beforehand and themovement timing and the movement speed are set beforehand, it becomespossible to always recognize at an optimum condition.

Further, in the above-described first and second alignment methods, whenthe recognition mark is read using the recognition means during itsmovement, in order to prevent reduction of position recognition accuracyby the enlargement of the recognition mark in the movement direction dueto influence of movement speed as shown in FIG. 3, it is preferred toshorten an exposure time of a shutter of the recognition means. Forexample, using an electronic shutter, the exposure time thereof is setat 1/100 second or less, preferably at 1/1000 second or less, whereby itbecomes possible to prevent the above-described mark enlargingrecognition. However, if the exposure time of the electronic shutter isset at 1/1000 second or less for example, the image becomes dark becauseof a lack of an amount of light. Although it is considered to use astrong light source in order to increase the amount of light, if thelight of such a strong light source is used, for example, as shown inFIG. 4, when a recognition mark G is read, smear phenomenon may occursuch that lines H trailed by a strong ray appear, and there is a fearthat the position recognition accuracy is reduced by this smearphenomenon. Accordingly, in order to suppress the influence of thissmear phenomenon to as little as possible, it is possible tosubstantially extinguish the lines H due to smear phenomenon by using astroboscopic emission carried out synchronously with the exposure timedue to the electronic shutter together with the electronic shutter,thereby preventing the reduction of the position recognition accuracy.

A mounting method according to the present invention comprises a methodfor using the above-described first or second alignment method, afterpositioning both objects, mounting one object onto the other object.Since it is not necessary to assure a settling time and the alignmenttime is shortened, it becomes possible to shorten the mounting tactgreatly.

The above-described one object comprises, for example, a chip, and theother object comprises, for example, a substrate. In the presentinvention, however, the “chip” means all objects with forms being bondedto a substrate regardless of the kind and size, such as an IC chip, asemiconductor chip, an optoelectronic element, a surface mounting partand a wafer. Further, the “substrate” means all objects with forms beingbonded to a chip regardless of the kind and size, such as a resinsubstrate, a glass substrate, a film substrate, a chip and a wafer.

Further, as the recognition means in the present invention, although,for example, a two-sight recognition means having sights in bothdirections toward upper and lower sides, and a recognition meansinserted into a position of a lower side of both objects (including adouble-lens camera), can be used, as its form, any type of recognitionmeans can be employed as long as the recognition mark can be recognized,such as a CCD camera, an infrared ray camera, an X-ray camera, sensors,etc.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a mounting apparatus to which an alignmentmethod according to an embodiment of the present invention can beapplied.

FIG. 2 is a diagram showing a settling time of a movable recognitionmeans in a conventional technology and an example of mark recognitiontiming according to the method of the present invention.

FIG. 3 is a plan view of each of recognition marks, showing a case wherea mark may be recognized at a condition of being enlarged when the markis recognized by a movable recognition means during its movement.

FIG. 4 is a plan view of a recognition mark showing smear phenomenon.

FIG. 5 is an explanation diagram showing an example of relationshipbetween a movement axis and a sight in a movable recognition means.

FIG. 6 is an explanation diagram showing an example of relationshipbetween a movement demand and a coordinate of a movement axis in amovable recognition means.

FIG. 7 is a schematic view of a mounting apparatus showing an example ofa case where upper and lower marks are recognized by shifting a positionof one recognition mark in the present invention.

FIG. 8 is a flowchart of an operation of an alignment method accordingto an embodiment of the present invention.

FIG. 9 is a flowchart of an operation of an alignment method accordingto another embodiment of the present invention.

FIG. 10 is a graph showing a measurement result in a case where upperand lower recognition marks are repeatedly read simultaneously andsynchronously by upper and lower cameras during movement of a two-sightrecognition means.

FIG. 11 is a graph showing a result of relative positions of upper andlower recognition marks by the present invention in the propertydepicted in FIG. 10.

FIG. 12 is a schematic view of a mounting apparatus to which analignment method according to a further embodiment of the presentinvention can be applied.

FIG. 13 is a schematic view of the mounting apparatus showing a nextoperation of the operation depicted in FIG. 12.

FIG. 14 is a schematic view of a mounting apparatus to which analignment method according to a still further embodiment of the presentinvention can be applied.

FIG. 15 is a schematic elevational view of a mounting apparatus to whichan alignment method according to a still further embodiment of thepresent invention can be applied.

FIG. 16 is a schematic side view of the mounting apparatus depicted inFIG. 15.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, desirable embodiments of the present invention will beexplained referring to figures.

As a mechanical constitution of an apparatus in the present invention,an apparatus similar to that shown in FIG. 1 can be used. In the presentinvention, as shown in FIG. 2, although a drive demand for the movementof recognition means 5 (a two-sight recognition means) is issued,without setting settling time T up to a complete stop as that in aconventional technology, recognition marks A, C (or B, D) are readduring the movement, the reading is carried out, for example, at a pointP2 shown in FIG. 2.

This position of point P2 for reading may be present within a range inwhich an image of a recognition mark can be read. For example, as shownin FIG. 5, if a sight 12 of the recognition means (a center of thesight) comes to a position 14, at which an image of recognition mark 13can be read, relative to a movement axis coordinate 11 of therecognition during movement due to an encoder or a magnetic scaleprovided in a recognition means movement mechanism or a recognitionmeans position detection mechanism, the reading can be started.

At that time, as shown in FIG. 6, even if the movement demand and themovement position (movement axis coordinate) are shifted from each otheras to a time axis, as long as only the position on the movement axiscoordinate at the time of image reading can be fed back accurately, itis possible to correct the read position of the recognition mark at thereading precisely to an actual absolute position of the recognitionmark, based on the feedback signal. By such a correction, regardless ofthe reading during movement, the absolute position of each recognitionmark can be identified at a high accuracy, and based on the result ofthe correction, objects can be positioned to each other.

In particular, as shown in FIG. 1, if reading upper and lowerrecognition marks A, C (or B, D) simultaneously and synchronously bytwo-sight recognition means 5 having a two-sight optical system onalmost the same axis, without being affected by a vibration and the likeduring movement, the positional relationship between upper and lowerrecognition marks can be recognized at a high accuracy, and based onthis, a high-accuracy alignment can be carried out.

In a case where upper and lower recognition marks cannot be readsimultaneously as they are, for example, in a case where an adhesive ora film is provided on one object side and a recognition mark is providedat a position outside of the object, it becomes possible to read both ofthe upper and lower recognition marks simultaneously by shifting aposition of the recognition mark of one object by a predetermined amounttogether with the object. Because this forcible shifting amount is aknown amount, it can be easily and precisely corrected when both objectsare positioned to each other. For example, as shown in FIG. 7, theposition of second object 4 is forcibly shifted by moving stage 3 sothat recognition mark A and recognition mark C′ come to the sameposition vertically, and at this state, upper and lower recognitionmarks A and C′ may be read simultaneously and synchronously. Thisforcible shifting movement amount may be corrected at the time ofpositioning of both objects. A similar method can be employed forrecognition marks B and D′.

An operation flow (an operation flow up to mounting) of a case, whereupper and lower recognition marks A, C (or B, D) are read simultaneouslyand synchronously without forcible movement, will be exemplified in FIG.8. Further, an operation flow (an operation flow up to mounting) of acase, where upper and lower recognition marks A, C′ (or B, D′) are readsimultaneously and synchronously with forcible movement, will beexemplified in FIG. 9. In flows shown in FIGS. 8 and 9, a feedback pulsefrom a linear scale (an encoder) provided in a movement mechanism (adrive mechanism) is used for recognition of a movement axis coordinateof a two-sight recognition means.

In the flow shown in FIG. 8, a head holding a first object (for example,a chip) is moved to a position of a height for reading a recognitionmark, and a two-sight recognition means is inserted between the firstobject and a second object (for example, a substrate). During movementof the two-sight recognition means, an encoder feedback pulse of amovement axis before complete stop is read as a mark recognitionposition, as well as images of recognition marks A, C are readsimultaneously and synchronously by upper and lower cameras of thetwo-sight recognition means. Further, it is preferred that the feedbackpulse is read by a linear scale provided on a table instead of anencoder, because the position can be precisely recognized without beingaffected by an influence from the encoder such as a backlash between itand the table or a thermal expansion.

The two-sight recognition means is moved to a next recognition position,and similarly, during movement of the two-sight recognition means, anencoder feedback pulse of a movement axis before complete stop is readas a mark recognition position, as well as images of recognition marksB, D are read simultaneously and synchronously by upper and lowercameras of the two-sight recognition means.

Although the two-sight recognition means is retreated after reading ofthe mark images, the above-described recognition positions of marks A, Cand marks B, D are corrected based on the feedback information of themovement axis at the time of the above-described image reading, and theabsolute positions of the recognition marks A, C and the recognitionmarks B, D are recognized.

Base on this recognition information of the absolute positions, thestage is moved and adjusted, and the alignment is carried out so thatthe relative positional relationship between both objects is controlledwithin a predetermined range in accuracy. After positioning, the head ismoved down, and the mounting of the first object onto the second objectis carried out. After mounting, the head is moved up, and a series ofmounting operations are completed.

In the flow shown in FIG. 9, a head holding a first object (for example,a chip) is moved to a position of a height for reading a recognitionmark, and a two-sight recognition means is inserted between the firstobject and a second object (for example, a substrate). A stage is movedso that a recognition mark C′ can be read within the same vertical sightas that for a recognition mark A. After movement of the mark, duringmovement of the two-sight recognition means, an encoder feedback pulseof a movement axis before complete stop is read as a mark recognitionposition, as well as images of recognition marks A, C′ are readsimultaneously and synchronously by upper and lower cameras of thetwo-sight recognition means. Even in this case, in a case where thecomplete stop of the stage side is difficult relative to the cameramovement time, it is preferred to also read a feedback pulse of anencoder on a table of the stage side. Further, a linear scale ispreferable to the encoder.

Data examples in the above-described case where recognition marks A, Care read simultaneously and synchronously by the upper and lower camerasare shown in FIGS. 10 and 11. FIG. 10 shows data of image readingpositions relative to a reference position in a case where the operationfor reading images of recognition marks A, C′ simultaneously andsynchronously by upper and lower cameras during movement of a two-sightrecognition means is repeated. As shown in FIG. 10, even if themeasurement was repeated by the same coordinate, the image readingposition of a single body of upper camera A or lower camera C′ was notstable during the movement of the two-sight recognition means, and adispersion of about 8 μm occurred. Namely, when mounting is carried outat this condition, a dispersion of about 8 μm occurs. However, in a casewhere an alignment is carried out by reading the images of recognitionmarks A, C′ simultaneously and synchronously by upper and lower cameras,the relative positions of the recognition marks A, C′ exhibit as shownin FIG. 11, it becomes possible to detect the relative errors to beabout 0.6 μm or less, and it is understood that the accuracy can begreatly increased. Further, by reading the encoder feedback pulse, thisdispersion of about 8 μm can be recognized as an absolute position andcan be cancelled. Therefore, even when an alignment accompanying θcorrection, which requires an absolute position of a rotational center,is carried out, its accuracy can be assured.

Further, the stage is moved so that it can read recognition mark B andrecognition mark D′ in the same vertical sight, and the two-sightrecognition means is moved to a next recognition position. Then,similarly to the above-described operation, during movement of thetwo-sight recognition means, an encoder feedback pulse of a movementaxis before complete stop is read as a mark recognition position, aswell as images of recognition marks B, D′ are read simultaneously andsynchronously by upper and lower cameras of the two-sight recognitionmeans.

Although the two-sight recognition means is retreated after reading themark images, the recognition positions of marks A, C′ and therecognition positions of marks B, D′ are calculated and corrected basedon the feedback information of the movement axis at the time of theabove-described image reading, and absolute positions of the recognitionmarks A, C′ and the recognition marks B, D′ are recognized.

The stage is moved and adjusted based on this recognition information ofthe absolute positions, and the alignment is carried out so that therelative positional relationship between both objects is controlledwithin a predetermined range in accuracy. After positioning, the head ismoved down, and the mounting of the first object onto the second objectis carried out. After mounting, the head is moved up, and a series ofthe mounting operations are completed.

Even in any operation shown in FIGS. 8 and 9, because it is notnecessary to set a settling time for complete stop by reading markimages during the movement of the recognition means, the alignment timeand the mounting tact can be greatly shortened. Further, because theabsolute positions of the recognition marks can be precisely recognizedby the correction based on the feedback information of the movement axisat the time of image reading, a high accuracy for the alignment can beassured at the same time.

Further, as aforementioned, if an exposure time is shortened by using anelectronic shutter when reading the recognition marks, an enlargementphenomenon of read mark as shown in FIG. 3 can be prevented, and evenwhen a strong light source is used in order to further shorten theexposure time, if a stroboscopic emission is carried out synchronouslywith the exposure, it becomes possible to suppress smear phenomenon asshown in FIG. 4 to as little as possible, and an even higher accuracy ofposition recognition can be achieved.

As such efficient alignment method and mounting method using thealignment method according to the present invention capable of carryingout at a high accuracy and for a short period of time, other embodimentscan be employed. For example, FIGS. 12 and 13 show a mounting apparatusto which an alignment method according to a further embodiment of thepresent invention is applied. In FIG. 12, positioning recognition marksA, B are provided on the lower surface of a first object 2 (for example,a chip) held by head 1, and positioning recognition marks C, D areprovided on the lower surface of a second object 4 (for example, asubstrate) held by stage 3. The portion of the second object 4, whichprotrudes from stage 3, is supported by a receiving member 6, andrecognition marks C, D are provided on the lower surface of thisprotruded portion. Although the receiving member 6 is formed from aglass capable of transmitting a measurement wave, it may be formed froma material capable of transmitting a measurement wave such as aninfrared ray or an X ray except glass. A recognition means 7 is providedat a position below both objects 2 and 4 so as to be able to be movedand controlled in position. In this embodiment, the recognition means 7comprises a single-sight recognition means having only an upward sight.Further, head 1 is provided so as to be able to be moved in a verticaldirection (Z direction), stage 3 is provided so as to be able to bemoved in a horizontal direction (X, Y directions) and a rotationaldirection (θ direction), and recognition means 7 is provided so as to beable to be moved in X, Y and Z directions, respectively.

In the mounting apparatus thus constructed, the alignment and themounting are carried out, for example, in order of the following steps.

(1) As shown in FIG. 12, recognition means 7 is moved to a positionbelow first object 2 held by head 1, particularly, to a position atwhich recognition mark A enters into the sight from the lower side.

(2) Recognition mark A of the first object 2 side is read.

(3) Recognition mark B of the first object 2 side is read by movingrecognition means 7.

(4) As shown in FIG. 13, in order to recognize second object 4, stage 3is moved and recognition means 7 is moved to a position at whichrecognition mark C enters into the sight from the lower side.

(5) Recognition mark C of the second object 4 side is read.

(6) Recognition mark D of the second object 4 side is read by movingrecognition means 7.

(7) A correction processing is carried out from the result of readingthe marks A, B, C and D.

(8) The position and posture of stage 3 are adjusted, and the relativepositional accuracy between both objects 2 and 4 is controlled within apredetermined range.

(9) Head 1 is moved down and the mounting is carried out, and aftermounting, head 1 is moved up.

The order of these operation steps may be changed arbitrarily in theabove-described steps (1) to (6).

FIG. 14 shows a mounting apparatus to which an alignment methodaccording to a still further embodiment of the present invention isapplied. In the apparatus shown in FIG. 14, similarly to that shown inFIG. 12, positioning recognition marks A, B are provided on the lowersurface of a first object 2 (for example, a chip) held by head 1, andpositioning recognition marks C, D are provided on the lower surface ofa second object 4 (for example, a substrate) held by stage 3 andreceiving member 6. A recognition means 8 comprising a double lenscamera, which has two lenses 8 a and 8 b, is provided at a positionbelow both objects 2 and 4 so as to be able to be moved and controlledin position, and this double lens camera is incorporated integrally intothe recognition means 8 capable of being controlled in position, namely,into a movement mechanism, at a condition of a fixed predeterminedrelative positional relationship.

In the mounting apparatus thus constructed, the alignment and themounting are carried out, for example, in order of the following steps.

(1) Recognition means 8 comprising a double lens camera is moved to aposition below first object 2 held by head 1, particularly, to aposition at which recognition mark A enters into the sight from thelower side.

(2) Recognition mark A of the first object 2 side and recognition mark Cof the second object 4 side are read simultaneously.

(3) Recognition mark B of the first object 2 side and recognition mark Dof the second object 4 side are read simultaneously by movingrecognition means 8 (also moving stage 3 in accordance with thepositional relationship between recognition marks).

(4) A correction processing is carried out from the result of readingthe marks A, B, C and D.

(5) The position and posture of stage 3 are adjusted, and the relativepositional accuracy between both objects 2 and 4 is controlled within apredetermined range.

(6) Head 1 is moved down and the mounting is carried out, and aftermounting, head 1 is moved up.

The above-described step (2) may be changed with the step (3).

FIGS. 15 and 16 show a mounting apparatus to which an alignment methodaccording to a still further embodiment of the present invention isapplied. In the apparatus shown in FIGS. 15 and 16, similarly to thatshown in FIG. 12, positioning recognition marks A, B are provided on thelower surface of a first object 2 (for example, a chip) held by head 1,and positioning recognition marks C, D are provided on the lower surfaceof a second object 4 (for example, a substrate) held by stage 3 andreceiving member 6. A recognition means 9 constructed as a double lenscamera by incorporating two cameras 9 a and 9 b separable from eachother into a movement mechanism is provided at a position below bothobjects 2 and 4 so as to be able to be moved and controlled in position.

In the mounting apparatus thus constructed, the alignment and themounting are carried out, for example, in order of the following steps.

(1) Recognition means 9 comprising a double lens camera of a two cameraseparate type is moved to a position below first object 2 held by head1, particularly, to a position at which recognition mark A enters intothe sight from the lower side.

(2) Recognition mark A and recognition mark B of the first object 2 sideare read simultaneously.

(3) In order to recognize second object 4, stage 3 is moved, andrecognition means 9 is moved to a position at which recognition mark Cof the second object 4 side enters into the sight from the lower side.

(4) Recognition mark C and recognition mark D of the second object 4side are read simultaneously. However, in a case where the relativepositional relationship between recognition marks A and B of the firstobject 2 side is different from the relative positional relationshipbetween recognition marks C and D of the second object 2 side, thereading is carried out after one camera in recognition means 9 is moved.

(5) A correction processing is carried out from the result of readingthe marks A, B, C and D.

(6) The position and posture of stage 3 are adjusted, and the relativepositional accuracy between both objects 2 and 4 is controlled within apredetermined range.

(7) Head 1 is moved down and the mounting is carried out, and aftermounting, head 1 is moved up.

The above-described step (2) may be changed with the step (3).

Thus, for the alignment method and the mounting method using thealignment method according to the present invention, various embodimentscan be employed. In the alignment method and the mounting method usingthe alignment method according to the present invention, by readingupper and lower alignment marks simultaneously, the accuracy increasesas compared with that in a conventional technology, it is not necessaryto assure a settling time for complete stop of a movable recognitionmeans, and the alignment time and the mounting tact can be greatlyshortened. Further, if an electronic shutter and a stroboscope are usedat the time of reading a recognition mark, an even higher accuracy forrecognition of positions can be achieved.

The alignment method and the mounting method using the alignment methodaccording to the present invention can be applied to any positioningbetween objects to be bonded and any mounting of positioned objects. Byapplying the present invention, a high-accuracy mounting becomespossible, and an alignment time and a mounting tact can be greatlyshortened.

1. An alignment method for positioning objects to be bonded to eachother by reading positioning recognition marks provided on both objectsby a two-sight recognition means having sights in directions toward bothobjects, said alignment method comprising a step of reading both of saidrecognition marks simultaneously and synchronously with each other. 2.The alignment method according to claim 1, wherein a two-sightrecognition means having sights in directions toward both objectspositioned at upper and lower sides is used as said two-sightrecognition means.
 3. The alignment method according to claim 2, whereina double lens camera positioned at a lower side of both objects is usedfor said two-sight recognition means.
 4. The alignment method accordingto claim 3, wherein said double lens camera is incorporated integrallyinto a movement mechanism.
 5. The alignment method according to claim 3,wherein said double lens camera is constructed by incorporating twocameras being separable into a movement mechanism.
 6. The alignmentmethod according to claim 1, wherein, when recognition marks of bothobjects are provided at positions impossible to read simultaneously, arecognition mark provided on one object is moved together with theobject to a position at which the recognition mark can be readsimultaneously with a recognition mark provided on the other object, andafter both recognition marks are simultaneously read synchronously, anabsolute position of said moved recognition mark is identified bycorrection in consideration of an amount of said movement.
 7. Thealignment method according to claim 6, wherein, when said one object ismoved to said position possible to be read simultaneously, said oneobject is reached to a recognition position prior to said recognitionmeans.
 8. The alignment method according to claim 6, wherein, when saidone object is moved to said position possible to be read simultaneously,said one object is reached to a recognition position simultaneously withsaid recognition means.
 9. The alignment method according to claim 6,wherein, when said one object is moved to said position possible to beread simultaneously, an absolute position of said recognition mark ofsaid one object is identified before complete stop of a table for movingsaid one object, based on a position feedback signal of said table. 10.The alignment method according to claim 9, wherein, when saidrecognition means reads each of said positioning recognition marksprovided on said objects, an exposure time is controlled by anelectronic shutter.
 11. The alignment method according to claim 10,wherein a stroboscopic emission is carried out synchronously with saidexposure time due to said electronic shutter.
 12. A mounting method formounting one object onto the other object to be bonded to each otherafter positioning both objects to each other by using an alignmentmethod, said alignment method positioning both objects to each other byreading positioning recognition marks provided on both objects by atwo-sight recognition means having sights in directions toward bothobjects, said alignment method comprising a step of reading both of saidrecognition marks simultaneously and synchronously with each other. 13.The mounting method according to claim 12, wherein a two-sightrecognition means having sights in directions toward both objectspositioned at upper and lower sides is used as said two-sightrecognition means.
 14. The mounting method according to claim 12,wherein a double lens camera positioned at a lower side of both objectsis used for said two-sight recognition means.
 15. The mounting methodaccording to claim 14, wherein said double lens camera is incorporatedintegrally into a movement mechanism.
 16. The mounting method accordingto claim 14, wherein said double lens camera is constructed byincorporating two cameras being separable into a movement mechanism. 17.The mounting method according to claim 12, wherein, when recognitionmarks of both objects are provided at positions impossible to readsimultaneously, a recognition mark provided on one object is movedtogether with the object to a position at which the recognition mark canbe read simultaneously with a recognition mark provided on the otherobject, and after both recognition marks are simultaneously readsynchronously, an absolute position of said moved recognition mark isidentified by correction in consideration of an amount of said movement.18. The mounting method according to claim 17, wherein, when said oneobject is moved to said position possible to be read simultaneously,said one object is reached to a recognition position prior to saidrecognition means.
 19. The mounting method according to claim 17,wherein, when said one object is moved to said position possible to beread simultaneously, said one object is reached to a recognitionposition simultaneously with said recognition means.
 20. The mountingmethod according to claim 17, wherein, when said one object is moved tosaid position possible to be read simultaneously, an absolute positionof said recognition mark of said one object is identified beforecomplete stop of a table for moving said one object, based on a positionfeedback signal of said table.
 21. The mounting method according toclaim 20, wherein, when said recognition means reads each of saidpositioning recognition marks provided on said objects, an exposure timeis controlled by an electronic shutter.
 22. The mounting methodaccording to claim 21, wherein a stroboscopic emission is carried outsynchronously with said exposure time due to said electronic shutter.